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visits member for 2 years, 8 months
seen Mar 20 at 4:52

Sep
27
comment In RSA, do I calculate d from e or e from d?
In general, I would trust this site for crypto more than wikipedia since things are vetted here pretty much immediately after they're written.
Sep
27
comment How to fairly select a random number for a game without trusting a third party?
Another fix is to require the number of random bits be higher than (say) 256, and disallow repeated digests. Or better, to force the 2nd publisher of a repeated digest to reveal first (better because it allows you conclusively identify cheaters).
Sep
22
comment Accelerating SHA-1
@fgrieu: Is there a way to see if I'm having cache misses and how much they're costing me?
Sep
22
comment Accelerating SHA-1
@Thomas: reducing my buffer results in no difference in runtime; I'm not sure why you think L1 cache matters here since we process data exactly once (I'm running SHA1 over an 8GiB file).
Sep
22
accepted Accelerating SHA-1
Sep
22
comment Accelerating SHA-1
@jug: I've never heard this before (that Intel is quite a bit faster on a single core)... can you point me at a reference for this? I'd like to see if switching hardware would help.
Sep
21
comment Accelerating SHA-1
@jug: I did find that link, which is what led me to updating to the latest OpenSSL. Unfortunately, it was no faster.
Sep
21
comment Accelerating SHA-1
@Samuel: I'm processing a single incoming stream arriving at 5Gbps from the network and I'm currently bottlenecked by SHA-1 at 2.6Gbps; you're right that SIMD is useful: the XMM and YMM registers are part of the SSE(1-4) instructions which are already used in the OpenSSL code.
Sep
21
revised Accelerating SHA-1
added 245 characters in body
Sep
20
revised Accelerating SHA-1
added 4 characters in body
Sep
20
comment Accelerating SHA-1
Thomas: the authors of the paper I cite in my answer claim that a GPU does help. But they talk about "SSL flows" so perhaps they are inducing parallelism this way?!
Sep
20
answered Accelerating SHA-1
Sep
20
comment Accelerating SHA-1
@fgrieu: I'm hashing 128KiB at a time via SHA_Update (OpenSSL) in a tight read loop. I need a hash for the entire file, so I cannot run hash invocations in parallel (since SHA1 needs the previous chaining value to start computing the next).
Sep
20
comment Accelerating SHA-1
I have some latitude with the protocol... you're thinking to hash separately on multiple cores?
Sep
20
asked Accelerating SHA-1
Sep
19
accepted How to forge Schnorr signatures if you can guess the challenge
Sep
19
comment Converting a stream cipher into a block cipher
I'm asking out of general interest; to me it's interesting if one primitive can be efficiently converted to the other.
Sep
18
accepted What is Identity-Based Encryption (IBE) and why is it “better”?
Sep
18
answered How do I apply differential cryptanalysis to a block cipher?
Sep
18
asked Converting a stream cipher into a block cipher